Isotope fractionation of selenium by biomethylation in microcosm incubations of soil

The natural abundance of stable Se isotopes in methylselenides reflects sources and formation conditions of methylselenides. We tested the effects of (i) different inorganic Se species spiked to soils and (ii) different soil samples on the extent of fungal biomethylation of Se and the Se isotope ratios (δ82/76Se) in methylselenides. Furthermore, we assessed the decrease of dissolved, bioavailable Se during three days of equilibration of the soils with Se-enriched solutions. We conducted closed microcosm experiments containing soil spiked with Se(IV) or Se(VI), a growth medium, and the fungus species Alternaria alternata for 11 d. The concentrations and isotope ratios of Se were determined in all components of the microcosm with multicollector ICP-MS. The equilibration of the spiked Se(IV) and Se(VI) for 3 d resulted in a decrease of dissolved, bioavailable Se concentrations by 32 to 44% and 8 to 14%, respectively. Very little isotope fractionation occurred during this phase, and it can be attributed to mixing of the added Se with the pre-existing Se in the soils and minor Se(IV) reduction in one experiment. In two of the incubated soils – moderately acidic roadside and garden soils – between 9.1 and 30% of the supplied Se(IV) and 1.7% of the supplied Se(VI) were methylated while in a strongly acidic forest soil no Se methylation occurred. The methylselenides derived from Se(IV) were strongly depleted in 82Se (δ82/76Se = − 3.3 to − 4.5‰) compared with the soil (0.16–0.45‰) and the added Se(IV) (0.20‰). The methylselenide yield of the incubations with Se(VI) was too small for isotope measurements. Our results demonstrate that Se source species and soil properties influence the extent of Se biomethylation and that the produced methylselenides contain isotopically light Se.

Accumulation of the pathogenic fungus Batrachochytrium dendrobatidis on the regressing tail of midwife toads Alytes obstetricans undergoing metamorphosis

Batrachochytrium dendrobatidis (Bd) is a fungus infecting the skin of amphibians. On metamorphosing animals the infection is difficult to detect because of the limited information concerning the location of Bd on the animals during this stage. Histological investigation revealed that Bd accumulated on the reabsorbing tail of metamorphosing animals. This observation may facilitate the detection of Bd in metamorphosing amphibians.

Non-naturalized alien plants receive fewer flower visits than naturalized and native plants in a Swiss botanical garden

Many animal-pollinated plant species have been introduced to non-native regions without their usual pollinators. Nevertheless, some of these alien species managed to establish reproducing naturalized populations, which might negatively affect native plants. Recent studies have shown that many naturalized alien species can readily attract native pollinators. However, it is not known whether alien species that have not established naturalized populations are less successful in attracting pollinators. Therefore, we tested whether flower-visitation rates are lower for non-naturalized aliens than for naturalized alien and native species. We conducted a comparative study on flower visitation of 185 native, 37 naturalized alien and 224 non-naturalized alien plant species in the Botanical Garden of Bern, Switzerland. Our phylogenetically corrected analyses showed that non-naturalized alien species received fewer flower visitors than both naturalized alien and native species. Native, naturalized alien and non-naturalized alien species were visited by similar flower-visitor communities. Furthermore, among the naturalized alien species, the ones with a broader distribution range in Switzerland received a more diverse set of flower visitors. Although it has been suggested that most alien plants can readily integrate into native plant–pollinator networks, we show evidence that the capacity to attract flower visitors in non-native regions is different for naturalized and non-naturalized alien plants. Therefore, we conclude that successful naturalization of alien plants may be related to flower visitation.

Petition wegen Rückberufung der Garden, beschlossen im Verein der Perliner [sic!] Tänzerinnen

Boberach: Mit Titelblattillustration: Ballett der Petenten mit Pickelhaube, darüber Spruchband: O kehre wieder!. - Welsch (Projektbearbeiter): Schilderung einer (fiktiven) Versammlung von Berliner Tänzerinnen, die für die Rückberufung des Gardekorps in die Hauptstadt petitionieren. Mit überwiegend schlüpfrigem Inhalt

Tagsbefehl vom 20. Mai 1848: Die nachfolgenden Beschlüsse des Verwaltungsrathes der Nationalgarde werden behufs genauer Darnachachtung zur allgemeinen Kenntniß gebracht: Erstens. Die Garden sind berechtiget, die Uniform auch außer Dienst zu tragen ...

Welsch (Projektbearbeiter): Dienstreglements die Bewaffnung sowie die Feldzeichen der Wiener Nationalgarde betreffend

Da wegen Consignirung der Garden die Wahlen heute nicht vollendet werden können ...

Welsch (Projektbearbeiter): Wegen der notwendigen Bereithaltung der Nationalgarde werden die Wahlen bis zum 21. Juni 1848 11 Uhr vormittags verlängert; anschließend erfolgt die Auszählung

An die Herren Garden der V. Abtheilung der akademischen Legion! Da nach den von dem Ministerium des Inneren ausgesprochenen Grundsätzen ...

Welsch (Projektbearbeiter): Bekanntgabe der Musterungstermine zur Säuberung der Akademischen Legion von denjenigen Mitgliedern, die nur deswegen in sie eintraten, um dem Dienst in der Nationalgarde zu entgehen

Mitbürger! Es verlautet, daß von Seite der Garden ein Angriff auf die vor den Linien stehenden Truppen beabsichtiget werde ...

Welsch (Projektbearbeiter): Warnung vor Angriffen der Nationalgarde auf das vor dem Linienwall stehende Militär und Aufruf, sich im Interesse der Stadt Wien und ihrer Bevölkerung "so lange als möglich defensiv zu verhalten"

Bekanntmachung: Der Ober-Commandant der Nationalgarde Wiens und der Umgebung gibt an die Garden und mobilen Corps ...

Welsch (Projektbearbeiter): Der polnische Generalleutnant Bem übernimmt die Organisation der Verteidigung Wiens

Bekanntmachung: Allen jenen Garden und Mitgliedern mobiler Corps, welche nicht auf den vor dem Feinde befindlichen Wachposten stehen ...

Welsch (Projektbearbeiter): Verbot des Tragens geladener Waffen für diejenigen Mobilgardisten, welche nicht direkt vor dem Feind Dienst tun

Kundmachung: Es kommen Fälle vor, daß Commandanten oder einzelne Garden im Uebermaß des Eifers ...

Welsch (Projektbearbeiter): Exemtion der Wiener Gemeinderäte von der Verpflichtung zum Wehrdienst in der Nationalgarde